The present invention relates to a mechanism for adjusting the tilt and/or height of a countertop or table top of a piece of furniture, including at least one lifting element, which acts on the countertop or table top and is connected to a drive gear mechanism.
With such known adjustment mechanisms, the tilt and/or height of the countertop or table top of a piece of furniture can be adjusted. The lifting element is embodied as a lifting scissors with which the countertop or table top can be raised and lowered. If the countertop or table top is in its lower position, the lifting scissors then assumes its lowermost position, in which its legs form a large obtuse angle with one another. To raise the top, it is therefore necessary to exert a great amount of energy, because due to the fact that the legs of the lifting scissors are disposed at an obtuse angle relative to one another, an unfavorable distribution of force occurs. In addition, already with small adjustment paths of the lifting scissors a relatively great lifting stroke of the countertop or table top occurs. As the adjustment process continues, the force relationships become more favorable, so that the lifting scissors can be actuated with less force. Of course, there then also occurs only a small lifting stroke. Thus, this known adjustment mechanism has a nonuniform force-stroke-ratio. The lifting scissors is in addition sensitive to transverse stresses, because as a result thereof the hingedly interconnected legs of the lifting scissors can easily be bent. In certain cases, the lifting scissors can then no longer be actuated. Furthermore, the lifting scissors require a considerable amount of space for their installation.
The object of the present invention is to embody an adjustment mechanism of the aforementioned general type in such a way that while being easy to handle and requiring only little space for installation, it has a nearly constant force-stroke-ratio.